Anyone got a spare Roland R8 power supply knocking around?

[TheBro]

Anyone got a spare Roland R8 power supply knocking around? Would be interesting it buying it if you do. Thanks in advance!!!

[Limo]

Found on Gearslutz:

Quote

Hi guys,

Your prayers for these Roland ACH power supplies to be manufactured again have been answered.

I have spent over 5k tearing down several Roland R5's and ACH power supplies in order to get the specs so that the the molds for these power supplies can be manufactured in order for the R8 and R5's can live! They will be ready in both US and UK versions from late 2020. They won't be cheap though I'm afraid as I'd like to recoup the costs incurred so probably around £80 (I think that's about $100 at the moment) but they are exactly the same specs as the original with the strange 3 pin connection and 4 meter total length of the power supply.

I've only had 150 of each type made up for now but the samples I have have been tested with a Roland R5 and it worked a treat!

I will put them up on eBay and Amazon so just search and you'll find them on there under the name "effects_pedal_power_supplies"
 

It’s in this thread: https://www.gearslutz.com/board/so-much-gear-so-little-time/957735-roland-r8-power-supply.html

And what dicks Roland are to use a power supply like that. Sheesh ...

[dr lopez]

50 squid mate

[TubularCorporation]

At least with Symetrix (who used a notoriously hard to replace, dual rail linear AC power supply with a something like 7 pin DIN connector in the 80s and early 90s) they were good enough to publish the full specs and pinout so you could make your own.  Of course you need either a custom would transformer or two separate trasnformers, so it ends up being expensive but the originals are easily $100 and notoriously unreliable because they were underspecced, so it's worth doing.  

 

That said, I still haven't made a power supply for the pretty decent half-rack compressor I got for $12 because it didn't include the power supply, but in theory it shouldn't be that hard. 

 

That R8 looks like a hassle but I'm pretty sure that's an obscure but standard plug type, so all you'd need to do is stick a bipolar 10v power supply that could handle the current draw of the R8 in a box with one of those connectors wired up to it.

 

Something like this with a bit of extra filtering and regulation to drop the voltage down to 10v would probably be more than adequate, although you'd still need to use a normal DC power supply of some kind with it:

 

https://www.amazon.com/DROK-Converter-Non-isolated-Regulator-Transformer/dp/B0752TRXDC/

 

The connector would be the hard part, might be better off replacing it.

 

[TubularCorporation]

This claims to work but it's one of those sketchy situations where they deliberately cover the actual connector in the photo so they can use the same one for everything they sell.

 

https://powercord.mobi/ac-power-adapter-for-roland-r-8-r8-mkii-drum-machine/

 

For a $8 adapter I'd risk it, at that price maybe not. 

 

I'd look into the possibility of swapping in a small IEC 60320 C6 connector and connecting the matching cable to some kind of off-the-shelf bipolar power supply.

 

 

If you have to get someone else to do it you probably won't save any money BUT you'd end up with an R8 that would be a lot easier to power, and if you could manage it without modifying the case it would be completely reversible.

[Limo]

8 hours ago, TubularCorporation said:

That R8 looks like a hassle but I'm pretty sure that's an obscure but standard plug type, so all you'd need to do is stick a bipolar 10v power supply that could handle the current draw of the R8 in a box with one of those connectors wired up to it.

Bipolar power supplies are not exactly plentiful, though, as I recently discovered when I was looking for a bench power supply for Eurorack. Also, be careful with the pinout: the markings on the back of the RD8 are wrong.

[TubularCorporation]

That's good to know about the pinout!

 

There are bipolar power supplies available as plain PCBs with no transformer for not much but most of them are 12v or 15v so you'd need additional circuitry.  The board I linked is a unipolar to bipolar converter with filtering that will take unipolar DC from 5v to 30v and give you +/- 12vdc and it's pretty simple to step that down to 10vdc, not as convenient as a straight bipolar power supply but one nice thing is you could use just about any DC wall wart or USB charger to power it.

 

There are also cheap bipolar switching supplies like this, which are by far the most convenient and inexpensive option but I have a feeling they'd need some filtering (and like everythign else they're 12v not 10v although some are adjustable):

https://www.ebay.com/itm/AC-100V-240V-To-DC-5V-12V-24V-36V-LED-Light-Drive-Power-Supply-Switch-Adapter/254256260282

 

I don't know, I'm a complete hack at this stuff.